U.S. patent application number 14/647197 was filed with the patent office on 2015-10-15 for vehicle, control apparatus and control method.
This patent application is currently assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA. The applicant listed for this patent is TOYOTA JIDOSHA KABUSHIKI KAISHA. Invention is credited to Tomoharu Maeda.
Application Number | 20150292464 14/647197 |
Document ID | / |
Family ID | 51020041 |
Filed Date | 2015-10-15 |
United States Patent
Application |
20150292464 |
Kind Code |
A1 |
Maeda; Tomoharu |
October 15, 2015 |
VEHICLE, CONTROL APPARATUS AND CONTROL METHOD
Abstract
A vehicle comprises: a storage battery configured to store
electric power; an internal combustion engine configured to be
started with electric power supplied from the storage battery; an
electric auxiliary configured to operate with the electric power
supplied from the storage battery; and a stop start controller
configured to perform a stop control of stopping the internal
combustion engine according to a driving condition of the vehicle
and a restart control of restarting the internal combustion engine
that has been stopped by the stop control. The stop start
controller includes: an auxiliary voltage acquirer configured to
obtain a measured auxiliary voltage value that denotes a voltage of
the electric auxiliary measured on occasion of start of the
internal combustion engine; and a feasibility determiner configured
to determine whether the stop control is feasible, based on the
measured auxiliary voltage value.
Inventors: |
Maeda; Tomoharu;
(Toyota-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOYOTA JIDOSHA KABUSHIKI KAISHA |
Toyota-shi, Aichi |
|
JP |
|
|
Assignee: |
TOYOTA JIDOSHA KABUSHIKI
KAISHA
Toyota-shi, Aichi-ken
JP
|
Family ID: |
51020041 |
Appl. No.: |
14/647197 |
Filed: |
December 27, 2012 |
PCT Filed: |
December 27, 2012 |
PCT NO: |
PCT/JP2012/008395 |
371 Date: |
May 26, 2015 |
Current U.S.
Class: |
290/38E |
Current CPC
Class: |
Y02T 10/48 20130101;
F02N 2300/2006 20130101; F02N 2200/101 20130101; F02N 11/084
20130101; F02N 2250/02 20130101; Y02T 10/40 20130101; F02N 2200/063
20130101; F02N 11/0825 20130101; F02N 2200/064 20130101; F02N
2300/2008 20130101; F02N 2200/044 20130101; F02N 2200/102 20130101;
F02N 11/0814 20130101; F02N 2200/062 20130101; F02N 2200/046
20130101; F02N 2200/061 20130101 |
International
Class: |
F02N 11/08 20060101
F02N011/08 |
Claims
1. A vehicle comprising: a storage battery configured to store
electric power; an internal combustion engine configured to be
started with electric power supplied from the storage battery; an
electric auxiliary configured to operate with the electric power
supplied from the storage battery; and a stop start controller
configured to perform a stop control of stopping the internal
combustion engine according to a driving condition of the vehicle
and a restart control of restarting the internal combustion engine
that has been stopped by the stop control, wherein the stop start
controller includes: an auxiliary voltage acquirer configured to
obtain a measured auxiliary voltage value that denotes a voltage of
the electric auxiliary measured on occasion of start of the
internal combustion engine; and a feasibility determiner configured
to determine whether the stop control is feasible, based on the
measured auxiliary voltage value.
2. The vehicle according to claim 1, wherein the feasibility
determiner includes: an auxiliary voltage estimator configured to
estimate an estimated auxiliary voltage value that denotes a
voltage of the electric auxiliary expected on occasion of next
restart control, based on the measured auxiliary voltage value; and
a determination switcher configured to switch over a result of
determination of whether the stop control is feasible, according to
the estimated auxiliary voltage value.
3. The vehicle according to claim 1, further comprising a battery
voltage estimator configured to estimate an estimated battery
voltage value that denotes a voltage of the storage battery
expected on occasion of next start of the internal combustion
engine, wherein the auxiliary voltage estimator includes: a
variation calculator configured to calculate a variation of the
estimated battery voltage value from a time when the measured
auxiliary voltage value has been measured, based on the estimated
battery voltage value; and an estimated value calculator configured
to calculate the estimated auxiliary voltage value based on the
measured auxiliary voltage value and the variation.
4. The vehicle according to claim 1, wherein the measured auxiliary
voltage value includes at least one of a measurement value that
denotes a voltage of the electric auxiliary measured on occasion of
start of the internal combustion engine accompanied with a start of
the vehicle, and a measurement value that denotes a voltage of the
electric auxiliary measured on occasion of restart of the internal
combustion engine accompanied with execution of the restart
control.
5. The vehicle according to claim 1, wherein the electric auxiliary
includes the stop start controller, the stop start controller
includes a terminal configured to receive the electric power
supplied from the storage battery, and a voltage of the electric
auxiliary is a voltage of the terminal.
6. A control apparatus, in a vehicle including a storage battery,
an internal combustion engine and an electric auxiliary, configured
to perform a stop control of stopping the internal combustion
engine according to a driving condition of the vehicle and a
restart control of restarting the internal combustion engine that
has been stopped by the stop control, the control apparatus
comprising: an auxiliary voltage acquirer configured to obtain a
measured auxiliary voltage value that denotes a voltage of the
electric auxiliary measured on occasion of start of the internal
combustion engine; and a feasibility determiner configured to
determine whether the stop control is feasible, based on the
measured auxiliary voltage value.
7. A control method, in a vehicle including a storage battery, an
internal combustion engine and an electric auxiliary, for
performing a stop control of stopping the internal combustion
engine according to a driving condition of the vehicle and a
restart control of restarting the internal combustion engine that
has been stopped by the stop control, the control apparatus
comprising: obtaining a measured auxiliary voltage value that
denotes a voltage of the electric auxiliary measured on occasion of
start of the internal combustion engine; and determining whether
the stop control is feasible, based on the measured auxiliary
voltage value.
Description
TECHNICAL FIELD
[0001] The present invention relates to a vehicle, a control
apparatus and a control method.
BACKGROUND ART
[0002] A vehicle equipped with an internal combustion engine runs
with power generated by the internal combustion engine. This
vehicle is equipped with a storage battery (battery) and electric
auxiliaries, in addition to the internal combustion engine. The
internal combustion engine is started with the electric power
supplied from the storage battery. The electric auxiliaries operate
with the electric power supplied from the storage battery. The
electric auxiliaries include, for example, various control devices,
an electronic control fuel injection device, an actuator for
transmission control and an electric power assisted steering.
[0003] As is known, the vehicle equipped with the internal
combustion engine performs idle reduction to reduce idling of the
internal combustion engine for the purpose of saving the fuel
consumption and reducing the emission gas. Idle reduction is also
expressed as idle stop, idling stop, engine stop at vehicle stop or
no idling. Idle reduction control for controlling idle reduction
(stop start control) includes a stop control of stopping the
internal combustion engine according to the driving condition of
the vehicle and a restart control of restarting the internal
combustion engine that has been stopped by the stop control.
[0004] Patent Literature 1 describes idle reduction control to
determine whether the stop control is feasible, based on the
voltage of the storage battery detected during a stop period of the
internal combustion engine. Patent Literature 2 describes idle
reduction control to determine whether the stop control is
feasible, based on the voltage of the storage battery detected on
the occasion of restart of the internal combustion engine by the
restart control.
CITATION LIST
Patent Literature
[0005] PTL 1: JP 2010-24906A
[0006] PTL 2: JP 2012-172567A
SUMMARY
Technical Problem
[0007] The idle reduction controls described in Patent Literatures
1 and 2, however, do not take into account a voltage drop between
the storage battery and the electric auxiliary and may fail to
ensure a voltage required for the operation of the electric
auxiliary on the occasion of restart of the internal combustion
engine by the restart control. The voltage drop in the electric
auxiliary is varied depending on the electrical specification of
the vehicle (for example, the length of a wiring for connecting the
storage battery with each electric auxiliary and the types of the
electric auxiliaries mounted on the vehicle) and the operating
conditions of the electric auxiliaries. Idle reduction control on
the assumption of a significant voltage drop in the electric
auxiliary may, however, lead to excessively reduce idle reduction
and fail to sufficiently save the fuel consumption and reduce the
emission gas.
[0008] There is accordingly a need to provide a technique that
enhances the effect of idle reduction while ensuring the operation
of the electric auxiliary. With respect to the vehicle that
performs idle reduction, other needs include cost reduction,
resource saving, easy manufacture, improvement of usability and
improvement of durability.
Solution to Problem
[0009] In order to solve at least part of the problems described
above, the invention may be implemented by the following
aspects.
[0010] (1) According to one aspect of the invention, there is
provided a vehicle. The vehicle comprises a storage battery
configured to store electric power; an internal combustion engine
configured to be started with electric power supplied from the
storage battery; an electric auxiliary configured to operate with
the electric power supplied from the storage battery; and a stop
start controller configured to perform a stop control of stopping
the internal combustion engine according to a driving condition of
the vehicle and a restart control of restarting the internal
combustion engine that has been stopped by the stop control. The
stop start controller includes an auxiliary voltage acquirer
configured to obtain a measured auxiliary voltage value that
denotes a voltage of the electric auxiliary measured on occasion of
start of the internal combustion engine; and a feasibility
determiner configured to determine whether the stop control is
feasible, based on the measured auxiliary voltage value. The
vehicle of this aspect determines whether the stop control is
feasible by taking into account the voltage of the electric
auxiliary. This results in enhancing the effect of idle reduction,
while ensuring the operation of the electric auxiliary.
[0011] (2) In the vehicle of the above aspect, the feasibility
determiner may include an auxiliary voltage estimator configured to
estimate an estimated auxiliary voltage value that denotes a
voltage of the electric auxiliary expected on occasion of next
restart control, based on the measured auxiliary voltage value; and
a determination switcher configured to switch over a result of
determination of whether the stop control is feasible, according to
the estimated auxiliary voltage value. The vehicle of this aspect
determines whether the stop control is feasible in a flexible
manner according to a variation in estimated auxiliary voltage
value.
[0012] (3) The vehicle of the above aspect may further comprise a
battery voltage estimator configured to estimate an estimated
battery voltage value that denotes a voltage of the storage battery
expected on occasion of next start of the internal combustion
engine. The auxiliary voltage estimator may include a variation
calculator configured to calculate a variation of the estimated
battery voltage value from a time when the measured auxiliary
voltage value has been measured, based on the estimated battery
voltage value; and an estimated value calculator configured to
calculate the estimated auxiliary voltage value based on the
measured auxiliary voltage value and the variation. The vehicle of
this aspect enhances the accuracy of the estimated auxiliary
voltage value.
[0013] (4) In the vehicle of the above aspect, the measured
auxiliary voltage value may include at least one of a measurement
value that denotes a voltage of the electric auxiliary measured on
occasion of start of the internal combustion engine accompanied
with a start of the vehicle and a measurement value that denotes a
voltage of the electric auxiliary measured on occasion of restart
of the internal combustion engine accompanied with execution of the
restart control. The vehicle of this aspect determines whether the
stop control is feasible, based on the measured auxiliary voltage
value measured at least one of the occasion of start of the vehicle
and the occasion of execution of the restart control.
[0014] (5) In the vehicle of the above aspect, the electric
auxiliary may include the stop start controller. The stop start
controller may include a terminal configured to receive the
electric power supplied from the storage battery. A voltage of the
electric auxiliary may be a voltage of the terminal. The vehicle of
this aspect enables the measured auxiliary voltage value to be
obtained readily, compared with the case of using a voltage of
another electric auxiliary.
[0015] The invention may be implemented by a variety of aspects
other than the vehicle. The invention may be actualized by, for
example, a control device for an internal combustion engine, a
control method of an internal combustion engine, and a computer
program that implements the control method.
BRIEF DESCRIPTION OF DRAWINGS
[0016] FIG. 1 is a diagram illustrating the configuration of a
vehicle;
[0017] FIG. 2 is a diagram illustrating the detailed configuration
of a battery sensor;
[0018] FIG. 3 is a flowchart showing a feasibility determination
process performed by a stop start controller of the vehicle;
[0019] FIG. 4 is a diagram illustrating one example of operation of
the stop start controller; and
[0020] FIG. 5 is a diagram illustrating another example of
operation of the stop start controller.
DESCRIPTION OF EMBODIMENTS
A. Embodiment
[0021] FIG. 1 is a diagram illustrating the configuration of a
vehicle 10. The vehicle 10 has an internal combustion engine 20 and
runs with the power generated by the internal combustion engine 20.
The vehicle 10 performs idle reduction to reduce idling of the
internal combustion engine.
[0022] The vehicle 10 includes a power transmission mechanism 30,
drive wheels 40, a starting motor 52, a generator 54, a storage
battery 60, a starter switch 72, an accelerator pedal sensor 74 and
a brake pedal sensor 76, in addition to the internal combustion
engine 20. The vehicle 10 also includes an internal combustion
engine controller 100, a stop start controller 200, electric
auxiliaries 300 and a battery sensor 700.
[0023] The internal combustion engine 20 of the vehicle 10 is a
machine configured to combust a fuel and take out power. The
internal combustion engine 20 is also called engine. According to
this embodiment, the internal combustion engine 20 is a gasoline
engine that uses gasoline as the fuel. According to another
embodiment, the internal combustion engine 20 may be a diesel
engine.
[0024] The internal combustion engine 20 is started with the
electric power supplied from the storage battery 60. According to
this embodiment, at start of the internal combustion engine 20, the
electric power supplied from the storage battery 60 is converted
into a rotational torque by the starting motor 52, and the internal
combustion engine 20 uses the rotational torque by the starting
motor 52 to start. The starting motor 52 is also called starter
motor.
[0025] The power transmission mechanism 30 of the vehicle 10
transmits the power of the internal combustion engine 20 to the
drive wheels 40. According to this embodiment, the power
transmission mechanism 30 includes a transmission, a differential
gear and a driveshaft.
[0026] The generator 54 of the vehicle 10 uses the power of the
internal combustion engine 20 to generate electric power. According
to this embodiment, the generator 54 is an alternator equipped with
a rectifier. The electric power generated by the generator 54 is
used to charge the storage battery 60 and operate various electric
auxiliaries.
[0027] The storage battery 60 of the vehicle 10 is a secondary
battery configured to store electric power. The storage battery 60
may also be called battery. According to this embodiment, the
storage battery 60 is a lead acid battery. According to another
embodiment, the storage battery 60 may be a lithium ion secondary
battery or a nickel hydride rechargeable battery. According to this
embodiment, the storage battery 60 is charged by the generator 54.
The storage battery 60 supplies electric power to the various
electric auxiliaries.
[0028] The starter switch 72 of the vehicle 10 receives a drive
start instruction and a drive stop instruction of the vehicle 10
from the driver of the vehicle 10. According to this embodiment,
the starter switch 72 is one of electric auxiliaries that operate
with the electric power supplied from the storage battery 60.
[0029] The accelerator pedal sensor 74 of the vehicle 10 detects
the operation state of an accelerator pedal (not shown) by the
driver of the vehicle 10. According to this embodiment, the
accelerator pedal sensor 74 is one of the electric auxiliaries that
operate with the electric power supplied from the storage battery
60.
[0030] The brake pedal sensor 76 of the vehicle 10 detects the
operation state of a brake pedal (not shown) by the driver of the
vehicle 10. According to this embodiment, the brake pedal sensor 76
is one of the electric auxiliaries that operate with the electric
power supplied from the storage battery 60.
[0031] The internal combustion engine controller 100 of the vehicle
10 is a control device configured to control the operation of the
internal combustion engine 20. The internal combustion engine
controller 100 is also called engine control unit (ECU). According
to this embodiment, when the starter switch 72 receives a drive
start instruction, the internal combustion engine controller 100
operates the starter motor 52 to start the internal combustion
engine 20. According to this embodiment, the internal combustion
engine controller 100 activates the internal combustion engine 20,
in response to an input signal from the accelerator pedal sensor 74
and an input signal from the brake pedal sensor 76. According to
this embodiment, the internal combustion engine controller 100 is
one of the electric auxiliaries that operate with the electric
power supplied from the storage battery 60.
[0032] The stop start controller 200 of the vehicle 10 is a control
device configured to perform idle reduction control (stop start
control) for controlling idle reduction of the internal combustion
engine 20. According to this embodiment, the stop start controller
200 is one of the electric auxiliaries that operate with the
electric power supplied from the storage battery 60. According to
another embodiment, the stop start controller 200 may be part of
the internal combustion engine controller 100.
[0033] The stop start controller 200 includes a terminal 202, a
voltage sensor 204, a communication interface (communication I/F)
206, another communication interface (communication I/F) 208, a
stop controller 212, a restart controller 214, an auxiliary voltage
acquirer 230 and a feasibility determiner 240.
[0034] The terminal 202 of the stop start controller 200 receives
the electric power supplied from the storage battery 60. The stop
start controller 200 operates with the electric power supplied to
the terminal 202. According to this embodiment, the terminal 202 is
connected with the storage battery 60 via a wiring 80. According to
this embodiment, the terminal 202 is electrically connected in
parallel with the other electric auxiliaries 300.
[0035] The voltage sensor 204 of the stop start controller 200 is a
sensor configured to detect a voltage that is to be applied to the
terminal 202. According to this embodiment, the terminal 202 is
electrically connected in parallel with the other electric
auxiliaries 300, so that the voltage detected by the voltage sensor
204 represents the voltage of the stop start controller 200, as
well as the voltage of the other electric auxiliaries 300.
[0036] The communication interface 206 of the stop start controller
200 communicates with the battery sensor 700 such as to allow for
transmission of information to and from the battery sensor 700.
According to this embodiment, the communication interface 206
receives, from the battery sensor 700, an estimated battery voltage
value EBe that denotes a voltage of the storage battery 60 expected
on the occasion of next start of the internal combustion engine 20.
According to this embodiment, the communication interface 206
conforms to LIN (local interconnect network).
[0037] The communication interface 208 of the stop start controller
200 communicates with the internal combustion engine controller 100
such as to allow for transmission of information to and from the
internal combustion engine controller 100. According to this
embodiment, the communication interface 208 conforms to CAN
(controller area network).
[0038] The stop controller 212 of the stop start controller 200
performs stop control to stop the internal combustion engine 20
according to the driving condition of the vehicle 10. The restart
controller 214 of the stop start controller 200 performs restart
control to restart the internal combustion engine 20 that has been
stopped through the stop control by the stop controller 212.
According to this embodiment, the stop controller 212 and the
restart controller 214 give corresponding instructions to the
internal combustion engine controller 100 via the communication
interface 208, so as to stop and restart the internal combustion
engine 20.
[0039] The auxiliary voltage acquirer 230 of the stop start
controller 200 obtains a measured auxiliary voltage value EAm that
denotes a voltage of the stop start controller 200 measured on the
occasion of start of the internal combustion engine 20. According
to this embodiment, the auxiliary voltage acquirer 230 obtains the
measured auxiliary voltage value EAm, based on a detection signal
from the voltage sensor 204. According to another embodiment, the
auxiliary voltage acquirer 230 may obtain the measured auxiliary
voltage value EAm, based on a detection signal from a voltage
sensor provided in at least one of the wiring 80 and another
electric auxiliary 300.
[0040] The feasibility determiner 240 of the stop start controller
200 determines whether the stop control by the stop controller 212
is feasible, based on the measured auxiliary voltage value EAm.
According to this embodiment, the feasibility determiner 240
includes an auxiliary voltage estimator 241 and a determination
switcher 248.
[0041] The auxiliary voltage estimator 241 of the feasibility
determiner 240 estimates an estimated auxiliary voltage value EAe
that denotes a voltage of the stop start controller 200 expected on
the occasion of next restart control by the restart controller 240,
based on the measured auxiliary voltage value EAm. According to
this embodiment, the auxiliary voltage estimator 241 includes a
variation calculator 242 and an estimated value calculator 244. The
variation calculator 242 of the auxiliary voltage estimator 241
calculates a variation DEBe of an estimated battery voltage value
EBe from the time when the estimated auxiliary voltage value EAe
has been measured, based on the estimated batter voltage value EBe
obtained from the battery sensor 700 via the communication
interface 206. The estimated value calculator 244 of the auxiliary
voltage estimator 241 calculates the estimated auxiliary voltage
value EAe, based on the measured auxiliary voltage value EAm
obtained by the auxiliary voltage acquirer 230 and the variation
DEBe calculated by the variation calculator 242.
[0042] The determination switcher 248 of the feasibility determiner
240 switches over the result of determination of whether the stop
control by the stop controller 212 is feasible, according to the
estimated auxiliary voltage value EAe estimated by the auxiliary
voltage estimator 241. Upon determination that the stop control is
feasible, the determination switcher 248 permits the stop
controller 212 to perform the stop control. Upon determination that
the stop control is not feasible, on the other hand, the
determination switcher 248 prohibits the stop controller 212 from
performing the stop control.
[0043] According to this embodiment, the functions of the stop
controller 212, the restart controller 214, the auxiliary voltage
acquirer 230 and the feasibility determiner 240 of the stop start
controller 200 are implemented by the operation of a CPU (central
processing unit) according to a computer program. According to
another embodiment, at least part of these functions may be
implemented by the operation of an ASIC (application specific
integrated circuit) based on its circuit configuration.
[0044] The electric auxiliaries 300 of the vehicle 10 operate with
the electric power supplied from the storage battery 60. According
to this embodiment, the electric auxiliaries 300 include at least
one of an electronic control fuel injection device, an actuator for
transmission control and an electric power assisted steering.
[0045] The battery sensor 700 of the vehicle 10 is a sensor
configured to detect the state of the storage battery 60. The
battery sensor 700 is also called accumulator sensor.
[0046] FIG. 2 is a diagram illustrating the detailed configuration
of the battery sensor 700. The battery sensor 700 includes a
voltage sensor 712, a current sensor 714, a temperature sensor 716,
an open circuit voltage estimator 732, a starting current measurer
734, a temperature estimator 736, a battery simulator 750, a state
of health estimator 762, a state of charge estimator 764, a battery
voltage estimator 766 and a communication interface (communication
I/F) 780.
[0047] The voltage sensor 712 of the battery sensor 700 is a sensor
configured to detect a voltage generated between a positive
terminal and a negative terminal of the storage battery 60. The
current sensor 714 of the battery sensor 700 is a sensor configured
to detect an electric current flowing from the positive terminal of
the storage battery 60. The temperature sensor 716 of the battery
sensor 700 is a sensor configured to detect an ambient temperature
of the storage battery 60.
[0048] The open circuit voltage estimator 732 of the battery sensor
700 estimates an open circuit voltage (OCV) of the storage battery
60, based on a detection signal from the voltage sensor 712, 714.
The starting current measurer 734 measures an electric current
flowing from the storage battery 60 at a start of the internal
combustion engine 20, based on a detection signal from the current
sensor 714. The temperature estimator 736 of the battery sensor 700
estimates an internal temperature of the storage battery 60, based
on a detection signal from the temperature sensor 716.
[0049] The battery simulator 750 of the battery sensor 700
virtually establishes a storage battery model simulating the
storage battery 60 and performs a simulation to estimate the state
of the storage battery 60 using this storage battery model.
According to this embodiment, the battery simulator 750 corrects
parameters of the storage battery model, based on an output signal
from at least one sensor among the voltage sensor 712, the current
sensor 714 and the temperature sensor 716.
[0050] The state of health estimator 762 of the battery sensor 700
estimates a state of health (SOH) of the storage battery 60, based
on the simulation by the battery simulator 750. The state of charge
simulator 764 of the battery sensor 700 estimates a state of charge
(SOC) of the storage battery 60, based on the simulation by the
battery simulator 750.
[0051] The battery voltage estimator 766 of the battery sensor 700
estimates the estimated battery voltage value EBe that denotes a
voltage of the storage battery 60 expected on the occasion of next
start of the internal combustion engine 20. According to this
embodiment, the estimated battery voltage value EBe shows a minimum
voltage of the storage battery 60 expected on the occasion of next
start of the internal combustion engine, as a state of function
(SOF) of the storage battery 60.
[0052] The communication interface 780 of the battery sensor 700
communicates with the stop start controller 200 such as to allow
for transmission of information to and from the stop start
controller 200. According to this embodiment, the communication
interface 780 sends the estimated battery voltage value EBe by the
battery voltage estimator 766 to the stop start controller 200.
According to this embodiment, the communication interface 780
conforms to LIN.
[0053] According to this embodiment, the functions of the open
circuit voltage estimator 732, the starting current measurer 734,
the temperature estimator 736, the battery simulator 750, the state
of health estimator 762, the state of charge estimator 764 and the
battery voltage estimator 766 of the battery sensor 700 are
implemented by the operation of a CPU according to a computer
program. According to another embodiment, at least part of these
functions may be implemented by the operation of an ASIC based on
its circuit configuration.
[0054] FIG. 3 is a flowchart showing a feasibility determination
process performed by the stop start controller 200 of the vehicle
10. The feasibility determination process of FIG. 3 is a process of
determining whether the stop control by the stop controller 212 is
feasible. According to this embodiment, the stop start controller
200 performs the feasibility determination process of FIG. 3 at
regular intervals (for example, at every several seconds).
[0055] On start of the feasibility determination process of FIG. 3,
the stop start controller 200 determines whether the internal
combustion engine 20 has been started after previous execution of
the feasibility determination process (step S110). The start of the
internal combustion engine 20 subjected to the determination at
step S110 includes a start of the internal combustion engine 20 by
the operation of the starter switch 72 and a restart of the
internal combustion engine 20 by the restart controller 214.
[0056] When the internal combustion engine 20 has been started
after previous execution of the feasibility determination process
(step S110: YES), the stop start controller 200 performs an
auxiliary voltage acquisition process (step S112). In the auxiliary
voltage acquisition process (step S112), the stop start controller
200 enables the auxiliary voltage acquirer 230 to obtain the
measured auxiliary voltage value EAm measured on the occasion of
previous start of the internal combustion engine 20.
[0057] After obtaining the measured auxiliary voltage value EAm
(step S112), the stop start controller 200 obtains an estimated
battery voltage value EBe1 that is the estimated battery voltage
value EBe estimated on the occasion of previous start of the
internal combustion engine 20, from the battery sensor 700 via the
communication interface 206 (step S114).
[0058] After the estimated battery voltage value EBe1 is obtained
(step S114) or when the internal combustion engine 20 has not been
started after previous execution of the feasibility determination
process (step S110: NO), the stop start controller 200 obtains an
estimated battery voltage value EBe2 that is the estimated battery
voltage value EBe estimated at the current moment, from the battery
sensor 700 via the communication interface 206 (step S120).
[0059] After obtaining the estimated battery voltage value EBe2
(step S120), the stop start controller 200 performs an auxiliary
voltage estimation process (step S140). In the auxiliary voltage
estimation process (step S140), the stop start controller 200
enables the auxiliary voltage estimator 241 to estimate the
estimated auxiliary voltage value EAe, based on the measured
auxiliary voltage value EAm.
[0060] According to this embodiment, in the auxiliary voltage
estimation process (step S140), the stop start controller 200
performs a variation calculation process (step S142). In the
variation calculation process (step S142), the stop start
controller 200 enables the variation calculator 242 to calculate
the variation DEBe, based on the estimated battery voltage value
EBe1 and the estimated battery voltage value EBe2. According to
this embodiment, the stop start controller 200 calculates the
variation DEBe according to Equation (1) given below:
DEBe=EBe2-EBe1 (1)
[0061] According to this embodiment, after performing the variation
calculation process (step S142) in the auxiliary voltage estimation
process (step S140), the stop start controller 200 performs an
estimated value calculation process (step S144). In the estimated
value calculation process (step S144), the stop start controller
200 enables the estimated value calculator 244 to calculate the
estimated auxiliary voltage value EAe, based on the measured
auxiliary voltage value EAm and the variation DEBe. According to
this embodiment, the stop start controller 200 calculates the
estimated auxiliary voltage value EAe according to Equation (2)
given below:
EAe=EAm+aDEBe (2)
[0062] According to this embodiment, "a" in Equation (2) is equal
to 1. According to another embodiment, "a" in Equation (2) may be
less than 1 or may be greater than 1. According to this embodiment,
"a" in Equation (2) is a constant. According to another embodiment,
"a" in Equation (2) may be a variable that varies according to the
state of the vehicle 10.
[0063] After calculating the estimated auxiliary voltage value EAe
(step S144), the stop start controller 200 performs a determination
switchover process (step S160). In the determination switchover
process (step S160), the stop start controller 200 enables the
determination switcher 248 to switch over the result of
determination of whether the stop control by the stop controller
212 is feasible, according to the estimated auxiliary voltage value
EAe.
[0064] According to this embodiment, in the determination
switchover process (step S160), the stop start controller 200
determines whether the estimated auxiliary voltage value EAe is
greater than a threshold value Eth (step S162). According to this
embodiment, the threshold value Eth is 7.2 V (volts). According to
another embodiment, the threshold value Eth may be smaller than 7.2
V or may be greater than 7.2 V.
[0065] When the estimated auxiliary voltage value EAe is greater
than the threshold value Eth (step S162: YES), the stop start
controller 200 determines that the stop control by the stop
controller 212 is feasible and permits the stop controller 212 to
perform the stop control (step S164). The stop start controller 200
then terminates the feasibility determination process of FIG.
3.
[0066] When the estimated auxiliary voltage value EAe is not
greater than the threshold value Eth (step S162: NO), the stop
start controller 200 determines that the stop control by the stop
controller 212 is not feasible and prohibits the stop controller
212 from performing the stop control (step S166).
[0067] The stop start controller 200 then terminates the
feasibility determination process of FIG. 3.
[0068] FIG. 4 is a diagram illustrating one example of operation of
the stop start controller 200. In the example of FIG. 4, the
vehicle 10 is initially not operated, and the internal combustion
engine 20 that has been stopped is started by operation of the
starter switch 72 (timing Ta1). In the example of FIG. 4, the stop
control by the stop controller 212 is prohibited by the feasibility
determiner 240 before and after the timing Ta1.
[0069] After the start of the internal combustion engine 20 (timing
Ta1), when the estimated auxiliary voltage value EAe is not greater
than the threshold value Eth (timings Ta2, Ta3), the stop start
controller 200 continues prohibition of the stop control by the
stop controller 212. When the estimated auxiliary voltage value EAe
becomes greater than the threshold value Eth with charge of the
battery sensor 700 (timing Ta4), the stop start controller 200
permits the stop controller 212 to perform the stop control.
[0070] FIG. 5 is a diagram illustrating another example of
operation of the stop start controller 200. In the example of FIG.
5, the vehicle 10 is not operated, and the internal combustion
engine 20 that has been stopped is started by operation of the
starter switch 72 (timing Tb1). In the example of FIG. 5, the stop
control by the stop controller 212 is prohibited by the feasibility
determiner 240 before and after the timing Tb1.
[0071] After the start of the internal combustion engine 20 (timing
Tb1), when the estimated auxiliary voltage value EAe is not greater
than the threshold value Eth (timing Tb2), the stop start
controller 200 continues prohibition of the stop control by the
stop controller 212. When the estimated auxiliary voltage value EAe
becomes greater than the threshold value Eth with charge of the
battery sensor 700 (timing Tb3), the stop start controller 200
permits the stop controller 212 to perform the stop control.
[0072] After the permission for the stop controller 212 to perform
the stop control (timing Tb3), upon satisfaction of a condition for
the stop control by the stop controller 212 (timing Tb4), the stop
start controller 200 enables the stop controller 212 to stop the
internal combustion engine 20. Subsequently, upon satisfaction of a
condition for the restart control by the restart controller 214
(timing Tb5), the stop start controller 200 enables the restart
controller 214 to restart the internal combustion engine 20.
[0073] After the restart of the internal combustion engine 20
(timing Tb5), while the estimated auxiliary voltage value EAe is
greater than the threshold value Eth (timings Tb6, Tb7), the stop
start controller 200 continues the permission for the stop
controller 212 to perform the stop control. When the estimated
auxiliary voltage value EAe becomes equal to or less than the
threshold value Eth with discharge of the storage battery 60
(timing Tb8), the stop start controller 200 prohibits the stop
controller 212 from performing the stop control.
[0074] The embodiment described above determines whether the stop
control by the stop controller 212 is feasible by taking into
account the voltage of the electric auxiliary. This results in
enhancing the effect of idle reduction, while ensuring the
operation of the electric auxiliary.
[0075] The above embodiment determines whether the stop control by
the stop controller 212 is feasible in a flexible manner according
to a variation in estimated auxiliary voltage value EAe.
[0076] The above embodiment calculates the estimated auxiliary
voltage value EAe, based on the measured auxiliary voltage value
EAm and the variation DEBe. This enhances the accuracy of the
estimated auxiliary voltage value EAe.
[0077] The above embodiment determines whether the stop control by
the stop controller 212 is feasible, based on the measured
auxiliary voltage value EAm that is measured on each of the
occasion of start of the vehicle 10 by the operation of the starter
switch 72 and the occasion of execution of the restart control by
the restart controller 214.
[0078] The above embodiment uses the voltage of the terminal 202
provided in the stop start controller 200 as the measured auxiliary
voltage value EAm and thus enables the measured auxiliary voltage
value EAm to be readily obtained, compared with the case of using a
voltage of another electric auxiliary.
B. Other Embodiments
[0079] The invention is not limited to any of the embodiment, the
examples and the modifications described above but may be
implemented by a diversity of other configurations without
departing from the scope of the invention. For example, the
technical features of the embodiment, examples or modifications
corresponding to the technical features of the respective aspects
described in Summary may be replaced or combined appropriately, in
order to solve part or all of the problems described above or in
order to achieve part or all of the advantageous effects described
above. Any of the technical features may be omitted appropriately
unless the technical feature is described as essential herein.
[0080] For example, at least part of the auxiliary voltage acquirer
230 and the feasibility determiner 240 may be provided in another
electric auxiliary in addition to the stop start controller 200 or
may be provided in another electric auxiliary in place of the stop
start controller 200.
[0081] The auxiliary voltage acquirer 230 may obtain an internal
voltage of the stop start controller 200, as the measured auxiliary
voltage value EAm. The auxiliary voltage acquirer 230 may also
obtain voltages of a plurality of electric auxiliaries, as the
measured auxiliary voltage value EAm.
REFERENCE SIGNS LIST
[0082] 10 vehicle
[0083] 20 internal combustion engine
[0084] 30 power transmission mechanism
[0085] 40 drive wheels
[0086] 52 starting motor
[0087] 54 generator
[0088] 60 storage battery
[0089] 72 starter switch
[0090] 74 accelerator pedal sensor
[0091] 76 brake pedal sensor
[0092] 80 wiring
[0093] 100 internal combustion engine controller
[0094] 200 stop start controller
[0095] 202 terminal
[0096] 204 voltage sensor
[0097] 206 communication interface
[0098] 208 communication interface
[0099] 212 stop controller
[0100] 214 restart controller
[0101] 230 auxiliary voltage acquirer
[0102] 240 feasibility determiner
[0103] 241 auxiliary voltage estimator
[0104] 242 variation calculator
[0105] 244 estimated value calculator
[0106] 248 determination switcher
[0107] 300 electric auxiliaries
[0108] 700 battery sensor
[0109] 712 voltage sensor
[0110] 714 current sensor
[0111] 716 temperature sensor
[0112] 732 open circuit voltage estimator
[0113] 734 starting current measurer
[0114] 736 temperature estimator
[0115] 750 battery simulator
[0116] 762 state of health estimator
[0117] 764 state of charge estimator
[0118] 766 battery voltage estimator
[0119] 780 communication interface
[0120] EAe estimated auxiliary voltage value
[0121] EAm measured auxiliary voltage value
[0122] EBe estimated battery voltage value
[0123] EBe1 estimated battery voltage value
[0124] EBe2 estimated battery voltage value
[0125] DEBe variation
[0126] Eth threshold value
* * * * *